Fleet-footed dinosaur (Dromaeosaurus albertensis), late Cretaceous, based on fossil from the Judith River Formation, Alberta, Canada. This small (6-foot high), bird-like theropod is reconstructed with a small plume of head feathers to suggest its bird relationship. One of the striking features of this dinosaur is the oversized claw on each foot, probably used to disembowel prey. Also characteristic of the dromaeosaurs is the inflexible tail, a counterbalancing aid when running, and the large grasping hands. Dromaeosaurs may have hunted in packs like wolves to bring down much larger prey.